Welcome to the world's largest online community of tomato growers! If this is your first visit, please take a few moments and register to become a member of our community and have full access to all of our forums. (some are exclusive to members only) For more details about how to register, please click here.

Ignorance more frequently begets knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science. --Charles Darwin

I am also looking to breed for improved beta- carotene. Maybe we could share info. Here is my latest, a F1 cross between a galapagos tomato and a pink heart. The plant is huge and the tomatoes are bigger then normal for a cross with a wild galapagos. Now I just have to select for orange colored fruit and increased size.
craig

I am also looking to breed for improved beta- carotene. Maybe we could share info. Here is my latest, a F1 cross between a galapagos tomato and a pink heart. The plant is huge and the tomatoes are bigger then normal for a cross with a wild galapagos. Now I just have to select for orange colored fruit and increased size.

I'd be glad to share information (and maybe even breeding stock), but I won't get my F1 cross until next year, as I didn't have the tomatoes (of the right kind) or my plan worked out until this summer. So I using this summer as a 'practice' for tomato breeding [I'd estimate that only about 1/3 of my crosses are 'taking'. Is this fairly standard for a beginner at tomato crossing?.] I'm not familiar with the Galapagos tomato. What's it like?

What I learned so far (plus questins):
1) Not all orange colors are created equal
2) Elevated beta carotene results from the presence of the gene B (The
tomato is orange-red) the highest levels result from the additional precense
of the modifier gene MOG (and an orange color).
3) Question: will high levels of beta-carotene cause unfavorable flavors? Can
this be bred around?
4) B is on the same chromosome as the gene for determinate growth and is
linked to it. Can this link be broken?

Next year I plan that my main tomato breeding will involve CaroRich, 97L97, and Opalka.

I prefer the taste of high carotene foods to low carotene versions of the same food.

Genes crossover between the paired chromosomes, so it's possible to break the linkage between two genes on the same chromosome. How frequently that happens depends on how close together the genes are located on the chromosome. If they are on opposite ends of the chromosome it's like they are not linked at all. If they are side by side then it would be much less likely to break the linkage. If you can find a gene-map containing both genes, and it has a centimorgan scale on it, then that is a measures the likelihood of the linkage being broken in a cross. 1 centimorgan = 1% chance. So if they are tightly linked you just have to grow more plants to break the linkage.

Here's an example of a gene map. In this particular cross, chromosomes 3 and 8 contain a QTL for carotene content. The B gene is located on Chromosome 6. So there are lots of opportunities for increased carotene content.

I would like to trade info and breeding stock. To be more precise the tomatoes come from the Galapagos islands but are called CHEESMANII. There are alot of cool things about cheesmanii but crossing with them is like starting from the beginning. Crossing to get the B gene is easy but keeping all the positives and getting a decent size is hard. You should google cheesmanii.
craig

I am already fermenting the seeds! I am going to try to plant a few and see what I can do before winter. Both of my crosses so far have been a nice deep orange. I need to start selecting for greater size now.

I can't post pictures at this time but I'm having an 'odd' result in the F2. I crossed Opalka X 97L97. Opalka is a large pointed heirloom indeterminate paste type and 97L97 is a determinate paste colored orange because it carries the B gene.

The F1 seemed to be as expected, there was slight size differences in fruit size and shape between the plants, but all the plants were indeterminate, orange colored, and about the size of 97L97.

I expected significant variation in the F2. I got them in late after significant groundhog damage, so none have ripened yet. I expected size variation, and some shape variation but all 7 of my F2s appear to be small, nippled ,longer than wide fruit that are much smaller than either original parent. I guess I have a problem with cross pollination, but is there any other thoughts why I would be seeing this? I would think I would see more variation given the F1 parent was a hybrid. The fruits thus far seem almost identical like I was at an F5 or something.

Chris, I had similar unexpected results - where the F2 were all very very similar to my F1 and looked to be easy to stablilize that type, but then the F3 turned out to be a very mixed bag.
Another one was at F4 and seemed to be quite stable, but then the F5 suddenly saw a load of segregation for shape. These were hearts that segregated into many subtypes including paste shapes, nipples or not, etc.

My impression is that the shape genetics of pointy fruit are very very complex. There may be some epistasis involved which prevents things being expressed as expected. Then with another shuffle, bingo out they come. Pretty baffling.
I was reading about it this spring, there are ??? seven I think different genes for 'pointy'. So crosses of two pointy fruit won't necessarily segregate as expected if there were only one gene for that.

I believe I am going to revise my approach. I think I am going to do some (F1XF1) crosses and (F1XHibeta). The F1s are already (XHibeta).

Quote:

Originally Posted by bower

Chris, I had similar unexpected results - where the F2 were all very very similar to my F1 and looked to be easy to stablilize that type, but then the F3 turned out to be a very mixed bag.
Another one was at F4 and seemed to be quite stable, but then the F5 suddenly saw a load of segregation for shape. These were hearts that segregated into many subtypes including paste shapes, nipples or not, etc.

My impression is that the shape genetics of pointy fruit are very very complex. There may be some epistasis involved which prevents things being expressed as expected. Then with another shuffle, bingo out they come. Pretty baffling.
I was reading about it this spring, there are ??? seven I think different genes for 'pointy'. So crosses of two pointy fruit won't necessarily segregate as expected if there were only one gene for that.

Well my F2's have mostly come in and their consistency is amazing (I earlier described them as 'nippled', but when fully developed they are an oval.

All the fruit are all ovals and about 1-1/2 inches long by about 1 inch. The are all orange with the skins blushed with a red hue. There is slight internal wall thickness variation, but is slight enough that I decided not to differentiate on that.

So all my F3 that have produced tomatoes so far (Plants 1 through 5), I decided not to keep separately, but am fermenting them together.

The Jaune Flamme X Shannon (plant 2) F2, though it was the shape and size I wanted, and appears very productive, was red, was very juicy, and the fruit walls were thin.

I might grow some out in 2018 to see if I get any differentiation, but I am planning several different approaches now.

One of the problems I'm fight is the following 97L97 has high Beta gene with the modifier gene (for higher beta carotene, but is determinate (but is a paste type)

Jaune Flamme has the high Beta gene and is indeterminate, but does not have the modifier gene (and is not a paste type).

The high Beta gene is on the same chromosome as the sp gene (Determinate) so is 'linked' to it (and is close enough that breakage between the two is fairly rare.

I'm looking to develop a paste that is indeterminate, and has both the high Beta and the Modiere

Thinking about the beta linkage... Last year I grew six F3 plants of a heart or paste shaped selection - from an F2 that was Beta/- (orange-red) and indeterminate. I expected to get 1/4 (roughly!) that was Beta/Beta and determinate because of the linkage (Zolotoe Serdtse parent line), but instead I had more Beta/- indeterminates again and no determinates at all in the six.

You made that great post about odds awhile ago, do you think you could up the ante just by growing more plants from your F2 or F3? I thought the result was 'unlucky' for me but it's not out of the question with half dozen plants.

I also like your strategy of crossing unstable generations, and of crossing sp/Beta with indeterminate Beta, where both conditions are linked, what will happen? Would be nice to see the result of some larger numbers in that cross.

Thinking about the beta linkage... Last year I grew six F3 plants of a heart or paste shaped selection - from an F2 that was Beta/- (orange-red) and indeterminate. I expected to get 1/4 (roughly!) that was Beta/Beta and determinate because of the linkage (Zolotoe Serdtse parent line), but instead I had more Beta/- indeterminates again and no determinates at all in the six.

You made that great post about odds awhile ago, do you think you could up the ante just by growing more plants from your F2 or F3? I thought the result was 'unlucky' for me but it's not out of the question with half dozen plants.

1) You've given me an interesting idea (more later) Thanks!
2) I started playing with some Punnett squares, assuming there is no breakage (Beta and self-pruning are very close on the chromosome). I run into problems with the existing F1's crossed together, I would get 3/4 orange-red and 1/4 red, but only 1/3 of the orange-reds have the indeterminate high beta with the modifier gene present but hidden. Think I'll still do it, but I'll have to grow out a good amount of progency of the 2nd generation to find what I'm looking for.
3) This is the 'good' idea you've given me. I'm going to cross my two beta varieties, and select for indeterminate + Modifier (3/16) Only then will I cross the resulting tomato with pastes.
4) The other crosses I talked about (F1 X high beta) I may yet pursue but I'll need to analyze the potentials with more Punnett squares)

Quote:

Originally Posted by bower

I also like your strategy of crossing unstable generations, and of crossing sp/Beta with indeterminate Beta, where both conditions are linked, what will happen? Would be nice to see the result of some larger numbers in that cross.

I'm going to probably do that as well (I also saved seed from the same F1 cross, but a different plant, so I can see if get a different result.

Wanted to post about what I've realized about the Hi-Beta breeding I've been attempting.

The tomato I'm trying to achieve is a high beta-carotene, indeterminate paste tomato.

At this time, I'm going to ignore the "paste" part and concentrate on achieving a high-beta indeterminate tomato.

However the gene for high-beta (B) is located on the same chromosome as the gene for indeterminate/determinate (which is noted as sp (self-pruning) so indeterminate is (sp+). The linkage is close enough that I've now realized that it is unlikely to break for the numbers of plants I can deal with (20+ with up to 45 or so if I grow no other tomatoes). So I have realized for breeding purposes I have to effectively treat the beta gene and it originating growth type as a unit.

There is a third gene I want for this tomato - designated as mog. This is a modifer gene that increases the beta carotene from 50-60% to near 90% only in the presence of the high beta gene. the one I want is the recessive form (I'm going to use just (m) as the designator for this gene in the further parts of this post.

So the tomato I want to ultimately acheive is sp+sp+BBmm

Again the genes are
sp+ - indeterminate
B - high-beta carotene (50-60% when alone)
m - in the presence of B increases beta-carotene to ~90%.

The main 4 tomatoes I've worked with thus far:

97L97 - A high beta-carotene breeding tomato genetics (spspBBmm) (it's determinate)Jaune Flammee - high-beta french tomato without the modifier gene: (sp+sp+BBMM)Opalka and Shannon - for this purpose they have similar genetics: (sp+sp+bbMM)

All these tomatoes have the R (red) gene which I'm going to ignore for the moment, but I wanted to note that B does not 'work' in the presence of the other form of yellow/orange tomatoes that are caused by the recessive (r) gene.

The one advantage I have is the coloring of the tomatoes shows me the beta/modfier genetics:

bb-- (modifier gene doesn't matter the fruit will be red )Red.pngB-M- (high Beta without modifier gene with be orange-red (orange, then developing an red blush (although the blush can be slow to appear) OrangeRed.pngB-mm (High Beta with modifier gene will be orange and never develop a red blush)Orange.png

So a cross between 97L97 and Opalka yields an F1 Hybrid of sp+spBbMm OrangeRed.png

and a cross with Jaune Flammee and Shannon yielded an F1 Hybrid of sp+sp+BbMM which is also OrangeRed.png

I thought of crossing the two hybrids but the results were disappointing. Also in looking at the Punnet square that instead of the 8X8 square you'd think of with 3 separate genes it is much smaller because you're handling the sp gene and the beta gene as a locked unit: